I'm not sure the term "fiscally liberal" describes a consistent set of beliefs as they're held by a group of people in the United States. For that matter neither does "fiscally conservative."
For example, why do a lot of "fiscal conservatives" support wasting trillions of dollars for decades in wars with no goal?
I think that's the trouble with so-called "fiscal conservativism." It holds that government should only be spending money on "the important stuff." What comprises the important stuff is anybody's guess.
because most people are not super smart, and don't think carefully about words, and get their thinking hijacked by powerful special interests.